Have any AI's been able to decode human vision 'thoughts'
There have been studies in University of Oregon and Kyoto University to be able to visualise thoughts and dreams on a screen using voxel values of an FMRI scan as input and an estimation of an image of the thoughts as the output. Instead of linking you to these studies and papers - you could just watch this episode of mind field where both these studies are demonstrated and linked.

The idea behind this is easier to understand if you have a good understanding of generative networks such as generative adversarial networks or so. Essentially in GAN's you'd map a known latent distribution to images in pixel-space. You would be doing the same thing here, just that the latent distribution would now be the FMRI scan input and the mapping would be made in a supervised setting where they are initially showed images. A very rough understanding of the idea can be drawn on these lines.